13,577 research outputs found
Statistical Methods in Topological Data Analysis for Complex, High-Dimensional Data
The utilization of statistical methods an their applications within the new
field of study known as Topological Data Analysis has has tremendous potential
for broadening our exploration and understanding of complex, high-dimensional
data spaces. This paper provides an introductory overview of the mathematical
underpinnings of Topological Data Analysis, the workflow to convert samples of
data to topological summary statistics, and some of the statistical methods
developed for performing inference on these topological summary statistics. The
intention of this non-technical overview is to motivate statisticians who are
interested in learning more about the subject.Comment: 15 pages, 7 Figures, 27th Annual Conference on Applied Statistics in
Agricultur
GPU Accelerated Discontinuous Galerkin Methods for Shallow Water Equations
We discuss the development, verification, and performance of a GPU
accelerated discontinuous Galerkin method for the solutions of two dimensional
nonlinear shallow water equations. The shallow water equations are hyperbolic
partial differential equations and are widely used in the simulation of tsunami
wave propagations. Our algorithms are tailored to take advantage of the single
instruction multiple data (SIMD) architecture of graphic processing units. The
time integration is accelerated by local time stepping based on a multi-rate
Adams-Bashforth scheme. A total variational bounded limiter is adopted for
nonlinear stability of the numerical scheme. This limiter is coupled with a
mass and momentum conserving positivity preserving limiter for the special
treatment of a dry or partially wet element in the triangulation. Accuracy,
robustness and performance are demonstrated with the aid of test cases. We
compare the performance of the kernels expressed in a portable threading
language OCCA, when cross compiled with OpenCL, CUDA, and OpenMP at runtime.Comment: 26 pages, 51 figure
Detection of equine atypical myopathy-associated hypoglycin A in plant material: Optimisation and validation of a novel LC-MS based method without derivatisation
Hypoglycin A (HGA) toxicity, following ingestion of material from certain plants, is linked to an acquired multiple acyl-CoA dehydrogenase deficiency known as atypical myopathy, a commonly fatal form of equine rhabdomyolysis seen worldwide. Whilst some plants are known to contain this toxin, little is known about its function or the mechanisms that lead to varied HGA concentrations between plants. Consequently, reliable tools to detect this amino acid in plant samples are needed. Analytical methods for HGA detection have previously been validated for the food industry, however, these techniques rely on chemical derivatisation to obtain accurate results at low HGA concentrations. In this work, we describe and validate a novel method, without need for chemical derivatisation (accuracy = 84â94%; precision = 3â16%; reproducibility = 3â6%; mean linear range R2 = 0.999). The current limit of quantitation for HGA in plant material was halved (from 1ÎŒg/g in previous studies) to 0.5ÎŒg/g. The method was tested in Acer pseudoplatanus material and other tree and plant species. We confirm that A. pseudoplatanus is most likely the only source of HGA in trees found within European pastures
Two-sided asymmetric subduction; implications for tectonomagmatic and metallogenic evolution of the Lut Block, Eastern Iran
West directed subduction zones show common characteristics, such as low structural elevation, deep trench, steep slab and a
conjugate back-arc basin that are opposite to those of the east directed subduction zones. The tectonomagmatic and
metallogenic setting of the Lut Block is still a matter of debate and several hypotheses have been put forward. Despite some
authors denying the influence of the operation of Benioff planes, the majority propose that it occurred beneath the Afghan
Block, while others consider that oceanic lithosphere was dragged under the Lut Block. Cu-Au porphyry deposits seem to
occur in an island arc geotectonic setting during the middle Eocene while Mo-bearing deposits are coincident with the
crustal thickening during Oligocene. We introduce new trace element and isotope geochemical data for granitoids and
structural evidences testifying the two-sided asymmetric subduction beneath both Afghan and Lut Blocks, with different
rates of consumption of oceanic lithosphere
Novel application assigned to toluquinol: inhibition of lymphangiogenesis by interfering with VEGF-C/VEGFR-3 signalling pathway
BACKGROUND AND PURPOSE
Lymphangiogenesis is an important biological process associated with the pathogenesis of several diseases, including metastatic
dissemination, graft rejection, lymphoedema and other inflammatory disorders. The development of new drugs that block
lymphangiogenesis has become a promising therapeutic strategy. In this study, we investigated the ability of toluquinol,
a 2-methyl-hydroquinone isolated from the culture broth of the marine fungus Penicillium sp. HL-85-ALS5-R004, to inhibit
lymphangiogenesis in vitro, ex vivo and in vivo.
EXPERIMENTAL APPROACH
We used human lymphatic endothelial cells (LECs) to analyse the effect of toluquinol in 2D and 3D in vitro cultures and in the
ex vivo mouse lymphatic ring assay. For in vivo approaches, the transgenic Fli1:eGFPy1 zebrafish, mouse ear sponges and cornea
models were used. Western blotting and apoptosis analyses were carried out to search for drug targets.
KEY RESULTS
Toluquinol inhibited LEC proliferation,migration, tubulogenesis and sprouting of new lymphatic vessels. Furthermore, toluquinol
induced apoptosis of LECs after 14 h of treatment in vitro, blocked the development of the thoracic duct in zebrafish and reduced
the VEGF-C-induced lymphatic vessel formation and corneal neovascularization in mice. Mechanistically, we demonstrated that
this drug attenuates VEGF-C-induced VEGFR-3 phosphorylation in a dose-dependentmanner and suppresses the phosphorylation
of Akt and ERK1/2.
CONCLUSIONS AND IMPLICATIONS
Based on these findings, we propose toluquinol as a new candidate with pharmacological potential for the treatment of
lymphangiogenesis-related pathologies. Notably, its ability to suppress corneal neovascularization paves the way for applications
in vascular ocular pathologies.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tech. This work has been
supported by personal funding by FP7-PEOPLE-2013-IEF Marie
Curie Postdoctoral Fellowship (MGC). Acknowledged are the
supporting grants from the Action de Recherche Concertée
(ARC) (Université de LiÚge), the Fonds de la Recherche
Scientifique-FNRS (F.R.S.-FNRS), the Foundation Against Cancer
(foundation of public interest), the Centre Anticancéreux prÚs
lâUniversitĂ© de LiĂšge, the Fonds LĂ©on Fredericq (University of
LiĂšge), the Interuniversity Attraction Poles Programme-Belgian
Science Policy (all from Belgium) and the Plan National Cancer
(« Service Public Federal » from Belgium). Research in the lab of
A.R.Q. and M.A.M. was supported by grants BIO2014-56092-R
(MINECO and FEDER) and P12-CTS-1507 (Andalusian
Government and FEDER)
Statistical Methods in Topological Data Analysis for Complex, High-Dimensional Data
The utilization of statistical methods an their applications within the new field of study known as Topological Data Analysis has has tremendous potential for broadening our exploration and understanding of complex, high-dimensional data spaces. This paper provides an introductory overview of the mathematical underpinnings of Topological Data Analysis, the workflow to convert samples of data to topological summary statistics, and some of the statistical methods developed for performing inference on these topological summary statistics. The intention of this non-technical overview is to motivate statisticians who are interested in learning more about the subject
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